function JSX() {
  // let books = ["DOM编程艺术","JS高级编程","React 实战"];
  let books = ["DOM编程艺术", "JS高级编程", "React 实战"];
  // let arr = [<li>{books[0]}</li>, <li>{books[1]}</li>, <li>{books[2]}</li>];
  // [<li>{book}</li>,<li>{book}</li>,<li>{book}</li>]
  // let arr = books.map(book=>{
  //   return <li>{book}</li>
  // })
  // let arr = books.map(book=><li>{book}</li>)
  return <ul>
    {books.map(book=><li key={book}>{book}</li>)}
  </ul>;
}
export default JSX;
